Brief Answer: Nothing you need to concerned about sir Detailed Answer: Hello sir and welcome. Thank you for writing to us. The black sputum that you noticed was clearly because of the marijuana that you smoked sir. Although, this can look alarming it is nothing you need to be concerned about. The sputum was black solely because of the smoke that you inhaled from smoking the marijuana. But the black sputum indicates that you have been smoking marijuana too often, try to avoid this sir. Although, this is nothing you need to be concerned about right now, I would advise you to try to avoid smoking marijuana as much as possible, as the long-term effects may be something you need to be concerned about. I hope you find my response helpful sir. Wishing you nothing but the best. Please feel free to write back to me for any further clarifications, I would be more than happy to help you. Best wishes.

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